The phrase "main artery" refers to the largest blood vessels in our bodies that carry blood from the heart to different parts of our body, kind of like the way roads and highways carry cars to different places. Full definition
The Mississippi, sister of the Ganges, Main artery of earth in the western world Is waiting to become In the spirit of America, a sacred river Whoever lifts up the Mississippi Lifts himself and all of America Whoever lifts himself Makes the great brown river smile (gse.harvard.edu)
Major highway truck accident shutting down main artery into Dallas. (rosenthalwadas.com)
Both lift lines for the Grizzly Gondola and Glacier Chair, the two main arteries from the base area, have merged. (skibig3.com)